A. Field of the Invention
The present invention relates to an apparatus for protecting a lithography mask having a pattern for manufacturing a micro-device, such as a semiconductor device or a liquid crystal display device. Also, the present invention relates to an exposure apparatus that transfers the pattern through exposure.
B. Description of the Related Art
Projection lithography technology may use Extreme Ultraviolet (EUV) light or radiation having a short wavelength (5 to 50 nm) to enhance the resolving power for micro-fabrication of semiconductor device circuits. Because an optical element of transmission-refraction type, such as a conventional lens, may not be used in such a wavelength range, an optical element of reflection type, such as a mirror, and a mask of reflection type may be used. See U.S. Pat. No. 6,825,481.
In an exposure apparatus for fabricating semiconductor device circuits, a pattern surface of a mask is protected with a pellicle or the like made from a thin film, so as to prevent a foreign substance from adhering to the pattern provided on the mask. In an exposure apparatus using EUV, however, an amount of EUV light as exposure light is significantly decreased when passing through a foreign-substance protection film such as a pellicle, resulting in decrease in throughput.